Surface combustion apparatus for



March 10, 1964 F. W. VAN LUlK, JR

SURFACE COMBUSTION APPARATUS FOR FLAME CHARGING Filed May 26, 1961 fm/enton 5221A M Vanda/I651; by 661$ j/figw Hr's Atzfor'n ey Unite States Patent 1 3,124,719 Patented Mar. 10, 1964 3,124,719 SURFACE C(DMBUSTEON APPARATUS; FUR FLAME CHARGHNG Frank W. Van Luik, .lr., Schenectady, N.Y., assignor to General Electric Company, a corporation of New York Filed May 26, 1961, Ser. No. 112,984 6 Claims. (Cl. 317-41) The present invention relates to a new and improved flame charging apparatus.

To be more specific, the invention relates to a new and improved flame charging apparatus for charging airborne aerosol particles.

It has been shown that charges may be readily imparted to airborne aerosol particles which ordinarily are electrically neutral by passing such airborne aerosol particles over a flame sustained from a source which is maintained at an electric potential different from ground with the flame source being disposed adjacent an electrically conductive member maintained at a different electric potential from the flame source. It has been shown also that the number of charged aerosol particles produced in this manner is a direct function of the size of the flame.

It is a primary object of this invention to provide a new and improved flame charging apparatus having an increased flame sustaining surface whereby large quantities of airborne aerosol particles may be readily charged.

In practicing the invention a flame particle charging apparatus is provided which comprises a hollow electrically conductive member fabricated from porous metal. The hollow porous metal member has an electrically insulated gaseous fuel supply connected to its hollow i11- terior whereby the gas seeps through the porous metal and will sustain combustion along its exterior surface. Electric terminal means are also provided for applying a high voltage direct electric potential to the porous metal member.

Other objects, features and many of the attendant advantages of this invention will be appreciated more readily as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein like parts in each of the several figures are identified by the same reference character, and wherein:

FIGURE 1 is a perspective view of a new and improved flame charging apparatus constructed in accordance with the invention;

FIGURE 2 is a partially broken-away blown up view of the porous metal member comprising a part of the flame charging apparatus shown in FIGURE 1; and

FIGURE 3 is a partially broken-away perspective view of a second embodiment of a flame charging apparatus constructed in accordance with the invention.

The embodiment of the invention shown in FIGURE 1 of the drawings includes a hollow flat box-like member 11. The details of constiuction of the box-like member 11 are better shown in the exploded view of FIGURE 2, wherein it can be seen that the member includes a pair of opposed flat surfaces 12 fabricated from a porous metal such as rough pig iron which has not been finished, or from a fire-d composition of fern'c oxide known as ferrite. Other porous [electrically conductive materials which are capable of supporting combustion on their surface, and are sufficiently porous may be used if desired. It should be noted that by porous is meant a memher having in elfect an infinite number of pores in a given space so that it is continuously permeable over its surface, as distinguished from a member having a finite number of holes or openings therein such as a solid pipe having a finite number of closely spaced gas jets or openings formed along its length. The two flat opposed porous metal surfaces of the box-like member 1 1 are supported by a pair of end plates 13 fabricated from stainless steel or other suitable material, and are closed at the sides by suitable side plates likewise formed from stainless steel. One end plate 13 has an electrically insulating bushing 1 1 secured thereto through which a gaseous fuel supply tube is connected to the interior of the boxlike member 11. The gaseous fuel is supplied under sufficient pressure to the interior of member 11 so that it seeps through the porous metal surfaces 12 and will sustain a flame over their entire outer surfaces as indicated by the arrow emanating from their surfaces. [he remaining end plate 13 of the box-like member 11 has a high voltage terminal 15 secured thereto which, as is best shown in FiGURE l, is connected to a high voltage direct current power supply 16. In one particular apparatus the high voltage supply provided from 1 to 10 kilovolts direct current. The end plate may be connected either to the positive or the negative terminals of the high voltage direct current power supply depending on whether it is desired to produce positive ions, and hence positively charged airborne aerosol particles, or electrons which will result in negatively charged airborne aerosol particles. The flame charging apparatus is completed by a pair of electrically conductive plates 17 and 18 which are spaced apart from the opposite porous metal surfaces 12 of the boxalike member 11, and may be grounded so that they are at a different potential. The plates 17, 18 are preferably rectangular in configuration, and may be fabricated from stainless steel or other suitable electrically conductive material. These plates are grounded so that they are at a different potential from the box-like member 111.

In operation, the air or other gaseous substance containing airborne aerosol particles is introduced into the space between the plates 17, 18 and the porous metal box 11. Prior to this, the gaseous fuel seeping through the porous metal surfaces :12 of the box 11 is ignited so that combustion is sustained over the entire outer surfaces 12 of the box-like member 11. As a result of the combustion process, both electrons and positive ions will be given off by the flame, and because of the electric potential applied to the box-like member 11, depending of course upon the polarity of this potential, either the electrons or the positive ions will be attracted back to the member 11, and the similarly charged particles will be propelled into the space between the plates 17, 18 and the box-like member 11. Assuming, for example, that the potential applied from the high voltage direct current power supply 16 to terminal 15 is negative, then the positive ions will be attracted back to the box-like member 11, and the electrons will be propelled into the space between the box-like member 11 and the plates 17 and 1-8. These electrons in travelling between the two surfaces will collide with, and unite with, the electrically neutral airborne aerosol particles likewise introduced into this space so as to impart a charge to the aerosol particles. The result is that the airborne aerosol particles which are now charged will be attracted to the plates 17 and .18 and thereby be removed from the atmosphere. It can be appreciated, that because of the relatively large surface provided by the porous metal sides 12 from which flames are sustained, almost the entire surface of the box-like member 11 is effective in producing the charged particles which combine with the airborne aerosol particles thereby making a very elfective and efficient flame charging apparatus.

A second embodiment of the invention is shown in FIGURE 3 of the drawings, and includes a hollow cylindrically shaped member 21. The cylindrical portion of the member 21 is formed of a porous metal such as rough pig iron or ferrite, and the end caps thereof may be formed from stainless steel. One of the end caps supports an insulating gas inlet 22 for a gaseous fuel supply, and the remaining end plate has a high voltage electrical terminal 23 secured thereto which in turn is connected to a high voltage direct current power supply 214.

V Disposed along opposite sides of the cylindrically shaped porous metal member 21, and spaced apart therefrom are a pair of semi-cylindrically shaped electrically conductive shields 25 and 2 6 which are preferably grounded.

In operation, the gaseous fuel supply connected through the electrically insulated gas inlet 22. is supplied under pressure to the hollow interior of the cylindrical porous metal member 21 Where it seeps up through the porous metal, and is ignited on the exterior surface so as to support combustion over the entire peripheral surface of the member. The gaseous atmosphere containing aerosol particles is introduced into the space between the semi-cylindrical conductive members 25 and 26 and the porous flame sustaining member 2d. Due to the high voltage potential applied from the source 24 to the porous electrically conductive flame sustaining member 21, charged particles of either positive or negative polarity will be repelled into the space between the semi-cylindrical members 2 and 26 and the porous metal 21. For example, if the potential supplied from the source 24 is negative in polarity, positive ions will be attracted from the flames back to the member 21, and electrons will be repelled into the space between the member 21 and .the semi-cylindrical conductive members 25 and 26. These electrons will collide with and adhere to the airborne aerosol particles being introduced into these spaces so as to impart a negative charge to the aerosol'particles. Thereafter, the charged airborne aerosol particles will be attracted to either of the semi-cylindrical plates 25 or 26 and thereby be removed from the atmosphere. -It can be appreciated that the embodiment of the invention shown in FIGURE 3 operates in much the same fashion as the FIGURE 1 embodiment, however it can be more eflicient if the semi-cylindrical shield 25, 26 are made to extend almost completely around the periphery of the cylindrical porous conductive member 21 which supports combustion around its entire outer periphery. Hence, the arrangement makes a highly efficient and effective flame particle charging apparatus.

Having described two embodiments of a new and improved fiame particle charging apparatus constructed in accordance with the invention, it is believed obvious that other modifications and variations of the invention are possible in the light of the above teachings. It is, therefore, to be understood that changes may be made in the particular embodiments of the invention described which are within the full intended scope of the invention as defined by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A flame particle charging apparatus comprising a hollow electrically conductive metal member having a surface which is continuously permeable and having an electrically insulated gaseous fuel supply inlet and electric terminal means for applying a high voltage electric potential to said permeable metal member.

2. The combination set forth in claim 1 further characterized by at least a second electrically conductive memher which conforms in shape to the exterior configuration of said permeable metal member, said second member being spaced from said permeable metal member and being maintained at a different electric potential.

3. A flame particle charging apparatus comprising a closed hollow relatively flat box-like electrically conductive member having flat opposed electrically conductive surfaces formed from continuously permeable metal and an electrically insulated gaseous fuel supply inlet for introducing combustible gases to the hollow interior of said member whereby the gaseous fuel will seep through the permeable metal surfaces and will sustain combustion on the exterior sides, and means for applying a high voltage direct current electric potential to said electrically conductive member.

4. The combination set forth in claim 3 further characterized by a pair of electrically conductive plates each spaced apart from respective ones of said opposed flat permeable metal surfaces of said box-like electrically conductive member with each of said plates being maintained at a potential different from said box-like member.

5. A flame particle charging apparatus comprising a closed hollow cylindrically shaped electrically conductive member having at least the cylindrical surface thereof formed from continuously permeable metal and having an electrically insulated gaseous fuel supply inlet for introducing combustible gases to the hollow interior of said member whereby the gaseous fuel will seep through the cylindrical continuously permeable metal surface and will sustain combustion on the exterior surface, and means for applying a high voltage direct current electrical potential to said electrically conductive member.

6. The combination set forth in claim 5 further characterized by at least a pair of electrically conductive semicylindrically shaped plates spaced on opposite sides apart from said cylindrically shaped member with each of said plates being maintained at a potential different from the potential of said cylindrically shaped member.

References Cited in the file of this patent UNITED STATES PATENTS 937,759 Blake Oct. 26, 1909 1,399,422 Chubb Dec. 6, 1921 2,604,936 Kaehni et al July 29, 1952 3,027,936 Lamp Apr. 3, 1962 

3. A FLAME PARTICLE CHARGING APPARATUS COMPRISING A CLOSED HOLLOW RELATIVELY FLAT BOX-LIKE ELECTRICALLY CONDUCTIVE MEMBER HAVING FLAT OPPOSED ELECTRICALLY CONDUCTIVE SURFACES FORMED FROM CONTINUOUSLY PERMEABLE METAL AND AN ELECTRICALLY INSULATED GASEOUS FUEL SUPPLY INLET FOR INTRODUCING COMBUSTIBLE GASES TO THE HOLLOW INTERIOR OF SAID MEMBER WHEREBY THE GASEOUS FUEL WILL SEEP THROUGH THE PERMEABLE METAL SURFACES AND WILL SUSTAIN COMBUSTION ON THE EXTERIOR SIDES, AND MEANS FOR APPLYING A HIGH VOLTAGE DIRECT CURRENT ELECTRIC POTENTIAL TO SAID ELECTRICALLY CONDUCTIVE MEMBER. 